Is anyone aware of any negative health effects fom sitting for long periods?
This could be arthritis, blood clots, deep vein thrombosis or nerve damage.

I generally sit for up to an hour before bedtime and get the occassional "pins and needles" etc.
A little pain is very common for most practicioners when sitting and is generally accepted as par for the course,
but recently I sometimes experienced some uncomfortable tingling for a while after going to bed.

My concern is that many of us could be slowly damaging our bodies.
I sit crosslegged (not lotus, half or burmese) on a thick squab with buttocks raised on a cushion. It is quite comfortable
but evetually the blood supply to the left leg is compromised by pressure from the right. All positions seem to have pros
and cons and this has worked the best for me so far. I am in my mid 30s and am in otherwise good health.

Don't just meditate. Make sure you also do exercises that use your legs (hiking, jogging, biking, etc..). I run for 1 hour every other day. I do feel some tingling after a long meditation but it doesn't affect my running so I think meditation is safe. Just make sure to combine it with exercises and you should be all right..

It's probably not blood flow, but rather compressed nerves which are being felt. A slight shifting from one buttock to the other, or swapping which leg is underneath, can often alleviate that, but with cross-legged postures by far the greater danger comes from knee damage due to a pinched meniscus. This is a very real danger; knee-pain is important not to ignore for the sake of meditation. You need a different posture, or greater flexibility, if knee pain arises. The numb bottom and pins-&-needles aren't terribly problematic, but you might consider a meditation bench as opposed to the cushion setup, especially if they are a consistent distraction which carry over into non-meditation times.

A daily stretching routine is extremely beneficial if done correctly.

"And how is it, bhikkhus, that by protecting oneself one protects others? By the pursuit, development, and cultivation of the four establishments of mindfulness. It is in such a way that by protecting oneself one protects others.

"And how is it, bhikkhus, that by protecting others one protects oneself? By patience, harmlessness, goodwill, and sympathy. It is in such a way that by protecting others one protects oneself.

You may consider asking this some abbots or monasteries. I guess they will be more familiar with health issues when monks happen to meditate more than a few hours per day.
I don't know of any cases where meditation led to any health problems at all.

nameless wrote:An hour is probably shorter than the amount of time people sit at work, on trains/buses/cars, watching a typical movie, watching tv, being on the computer etc.

That's the point. E.g. many people also put too much pressure on the knees or the back when lifting things, when standing or just by sleeping on the wrong mattress. Most people also don't train their musculature. During the time of the Buddha people certainly made more use of their legs than most of us do nowadays

If this uncomfortable "tingling" keeps showing up, please visit a doc just to make sure there is nothing serious going on. Take care!
Alobha

Fortunately my job involves a moderate amount of physical activity and I regularly practice Taiji in the mornings and evenings. This probably counteracts some of the effects of sitting for long periods.

I would be interested to hear of other peoples experiences of discomfort when sitting and how they deal with it.

I can recall from the first retreat I went on, Mr Goenkas' challenge to sit with "fierce determination" for one hour, and not to be distracted by physical discomforts when sitting. Followed by agonising sessions, and then sometimes a kind of trancendence of pain. Sometimes one could barely walk afterward, other times I could have leapt up and done a little dance. At home it can be fairly similar, but one feels less inclined to push oneself as hard.

Given the emphasis on sitting meditation within the Buddhist tradition I'm surprised so little is said about it, the history, the reasons for the various postures, the hands, the appropriate way to sit. Just the basic physical mechanical aspect. 2500 years experience should yield something.

Where's the manual on best practice?
The Zen Tradition of course takes it quite seriously I understand.

I sit crosslegged and meditate for a hour each day.i use to think i'd get pins and needles but i don't..the only problem is sometimes i feel a certain pain on my knee..i Never ignore this pain..or any other i deem "alarming".. i'd gently stretch out my legs and find a more comfortable position...there are usually no other problems that reoccure..i also do leg exercises generaly.Oh and stretching before meditation helps also.

daniel p wrote:Given the emphasis on sitting meditation within the Buddhist tradition I'm surprised so little is said about it, the history, the reasons for the various postures, the hands, the appropriate way to sit. Just the basic physical mechanical aspect. 2500 years experience should yield something.

Where's the manual on best practice?

The history as the Bodhisatta would have come upon it is possibly encapsulated by the formless attainments; see The Origin of Buddhist Meditation by A. Wynne. In any event, it was certainly an early Upanisadic milieu.

If, by the 'various postures' you mean things such as lotus, half-lotus, Burmese, seiza, and so on, those are all simple variations with no functional purpose apart from which style suits ones individual physiology. India circa 400 BCE was largely a place of sitting on the ground, whereupon "folding legs under" was a simple call to sit normally (!) without ones legs thrown askew, and "setting ones back straight" was a simple call not to slouch in order to prevent back strain and facilitate sitting for long periods. It's akin to a recipe on how to make a peanut butter sandwich. The first instruction is not a method to make bread from scratch, because it's assumed the bread is common and at hand. So, too, sitting on the ground.

(An esotericist will accept special significance for a straight back, usually involving either the chakras or the meridians. On a related note, gently resting your tongue somewhere on the roof of your mouth can prevent saliva from accumulating and leading to distracting/frequent swallowing, yet here again an esotericist will observe an important energetic function for this meditative tool.)

The hands needn't be in any mudra or any particular place, but they should rest gently in the lap such that (a) the shoulders aren't twisted into shoulder- and back-wearying shapes, allowing them to be down and away from the ears to prevent neck tension, and (b) you don't fidget with them (as can happen, for example, when trying to make kuji-kiri or mimic buddharupas). As always, the primary goal for the body is the ability to relax without inviting sloth-&-torpor (thīna-middha), ultimately leading to a habitual seated posture that can be assumed and maintained without the flurry-and-worry (uddhacca-kukkucca) of the beginner.

"And how is it, bhikkhus, that by protecting oneself one protects others? By the pursuit, development, and cultivation of the four establishments of mindfulness. It is in such a way that by protecting oneself one protects others.

"And how is it, bhikkhus, that by protecting others one protects oneself? By patience, harmlessness, goodwill, and sympathy. It is in such a way that by protecting others one protects oneself.

daverupa wrote: India circa 400 BCE was largely a place of sitting on the ground, whereupon "folding legs under" was a simple call to sit normally (!) without ones legs thrown askew, and "setting ones back straight" was a simple call not to slouch in order to prevent back strain and facilitate sitting for long periods.

To which I could add that it is still the case today for many in Asia (and other places) that they are quite used to sitting on the ground. While I do find that there is some advantage in stability to sitting on the ground vs in a chair, there's nothing magical about the particular position as far as Buddhist meditation instructions are concerned. In fact, I think it's very useful to realise that what is being instructed in the suttas is to sit comfortably.